On 04/10/2018 09:47 AM, Vikas Sharma wrote:
Thanks Adrian and Edison, I also think so. At the moment I have 2
masters, as soon as slave is promoted to master it starts its own
timeline and application might have added data to either of them or
both, only way to find out correct master now is the instance with max
count of data in tables which could incur data loss as well. Correct me
if wrong please?
Not sure max count is necessarily a valid indicator:
1) What if there was a legitimate large delete process?
2) The application/end users where looking at two different views of the
data at different points in time. Just because the count is higher does
not mean the data is actually valid.
Thanks and Regards
Vikas
On Tue, Apr 10, 2018, 17:29 Adrian Klaver <adrian.klaver@xxxxxxxxxxx
<mailto:adrian.klaver@xxxxxxxxxxx>> wrote:
On 04/10/2018 08:04 AM, Vikas Sharma wrote:
> Hi Adrian,
>
> This can be a good example: Application server e.g. tomcat having two
> entries to connect to databases, one for master and 2nd for Slave
> (ideally used when slave becomes master). If application is not
able to
> connect to first, it will try to connect to 2nd.
So the application server had a way of seeing the new master(old slave),
in spite of the network glitch, that the original master database
did not?
If so and it was distributing data between the two masters on an unknown
schedule, then as Edison pointed out in another post, you really have a
split brain issue. Each master would have it's own view of the data and
latest update would really only be relevant for that master.
>
> Regards
> Vikas
>
> On 10 April 2018 at 15:26, Adrian Klaver
<adrian.klaver@xxxxxxxxxxx <mailto:adrian.klaver@xxxxxxxxxxx>
> <mailto:adrian.klaver@xxxxxxxxxxx
<mailto:adrian.klaver@xxxxxxxxxxx>>> wrote:
>
> On 04/10/2018 06:50 AM, Vikas Sharma wrote:
>
> Hi,
>
> We have postgresql 9.5 with streaming
replication(Master-slave)
> and automatic failover. Due to network glitch we are in
> master-master situation for quite some time. Please,
could you
> advise best way to confirm which node is latest in terms of
> updates to the postgres databases.
>
>
> It might help to know how the two masters received data when they
> where operating independently.
>
>
> Regards
> Vikas Sharma
>
>
>
> --
> Adrian Klaver
> adrian.klaver@xxxxxxxxxxx <mailto:adrian.klaver@xxxxxxxxxxx>
<mailto:adrian.klaver@xxxxxxxxxxx <mailto:adrian.klaver@xxxxxxxxxxx>>
>
>
--
Adrian Klaver
adrian.klaver@xxxxxxxxxxx <mailto:adrian.klaver@xxxxxxxxxxx>
--
Adrian Klaver
adrian.klaver@xxxxxxxxxxx
